--- /dev/null
+/**************************************************************************
+ *
+ * Copyright © 2010 Jakob Bornecrantz
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+#define USE_TRACE 0
+#define WIDTH 300
+#define HEIGHT 300
+#define NEAR 30
+#define FAR 1000
+#define FLIP 0
+
+/* pipe_*_state structs */
+#include "pipe/p_state.h"
+/* pipe_context */
+#include "pipe/p_context.h"
+/* pipe_screen */
+#include "pipe/p_screen.h"
+/* PIPE_* */
+#include "pipe/p_defines.h"
+/* TGSI_SEMANTIC_{POSITION|GENERIC} */
+#include "pipe/p_shader_tokens.h"
+/* pipe_buffer_* helpers */
+#include "util/u_inlines.h"
+
+/* constant state object helper */
+#include "cso_cache/cso_context.h"
+
+/* u_sampler_view_default_template */
+#include "util/u_sampler.h"
+/* debug_dump_surface_bmp */
+#include "util/u_debug.h"
+/* util_draw_vertex_buffer helper */
+#include "util/u_draw_quad.h"
+/* FREE & CALLOC_STRUCT */
+#include "util/u_memory.h"
+/* util_make_[fragment|vertex]_passthrough_shader */
+#include "util/u_simple_shaders.h"
+
+/* softpipe software driver */
+#include "softpipe/sp_public.h"
+
+/* null software winsys */
+#include "sw/null/null_sw_winsys.h"
+
+/* traceing support see src/gallium/drivers/trace/README for more info. */
+#if USE_TRACE
+#include "trace/tr_screen.h"
+#include "trace/tr_context.h"
+#endif
+
+struct program
+{
+ struct pipe_screen *screen;
+ struct pipe_context *pipe;
+ struct cso_context *cso;
+
+ struct pipe_blend_state blend;
+ struct pipe_depth_stencil_alpha_state depthstencil;
+ struct pipe_rasterizer_state rasterizer;
+ struct pipe_sampler_state sampler;
+ struct pipe_viewport_state viewport;
+ struct pipe_framebuffer_state framebuffer;
+ struct pipe_vertex_element velem[2];
+
+ void *vs;
+ void *fs;
+
+ float clear_color[4];
+
+ struct pipe_buffer *vbuf;
+ struct pipe_texture *target;
+ struct pipe_texture *tex;
+ struct pipe_sampler_view *view;
+};
+
+static void init_prog(struct program *p)
+{
+ /* create the software rasterizer */
+ p->screen = softpipe_create_screen(null_sw_create());
+#if USE_TRACE
+ p->screen = trace_screen_create(p->screen);
+#endif
+ p->pipe = p->screen->context_create(p->screen, NULL);
+ p->cso = cso_create_context(p->pipe);
+
+ /* set clear color */
+ p->clear_color[0] = 0.3;
+ p->clear_color[1] = 0.1;
+ p->clear_color[2] = 0.3;
+ p->clear_color[3] = 1.0;
+
+ /* vertex buffer */
+ {
+ float vertices[4][2][4] = {
+ {
+ { 0.9f, 0.9f, 0.0f, 1.0f },
+ { 1.0f, 1.0f, 0.0f, 1.0f }
+ },
+ {
+ { -0.9f, 0.9f, 0.0f, 1.0f },
+ { 0.0f, 1.0f, 0.0f, 1.0f }
+ },
+ {
+ { -0.9f, -0.9f, 0.0f, 1.0f },
+ { 0.0f, 0.0f, 1.0f, 1.0f }
+ },
+ {
+ { 0.9f, -0.9f, 0.0f, 1.0f },
+ { 1.0f, 0.0f, 1.0f, 1.0f }
+ }
+ };
+
+ p->vbuf = pipe_buffer_create(p->screen, 16, PIPE_BUFFER_USAGE_VERTEX, sizeof(vertices));
+ pipe_buffer_write(p->screen, p->vbuf, 0, sizeof(vertices), vertices);
+ }
+
+ /* render target texture */
+ {
+ struct pipe_texture tmplt;
+ memset(&tmplt, 0, sizeof(tmplt));
+ tmplt.target = PIPE_TEXTURE_2D;
+ tmplt.format = PIPE_FORMAT_B8G8R8A8_UNORM; /* All drivers support this */
+ tmplt.width0 = WIDTH;
+ tmplt.height0 = HEIGHT;
+ tmplt.depth0 = 1;
+ tmplt.last_level = 0;
+ tmplt.tex_usage = PIPE_TEXTURE_USAGE_RENDER_TARGET;
+
+ p->target = p->screen->texture_create(p->screen, &tmplt);
+ }
+
+ /* sampler texture */
+ {
+ uint32_t *ptr;
+ struct pipe_transfer *t;
+ struct pipe_texture t_tmplt;
+ struct pipe_sampler_view v_tmplt;
+
+ memset(&t_tmplt, 0, sizeof(t_tmplt));
+ t_tmplt.target = PIPE_TEXTURE_2D;
+ t_tmplt.format = PIPE_FORMAT_B8G8R8A8_UNORM; /* All drivers support this */
+ t_tmplt.width0 = 2;
+ t_tmplt.height0 = 2;
+ t_tmplt.depth0 = 1;
+ t_tmplt.last_level = 0;
+ t_tmplt.tex_usage = PIPE_TEXTURE_USAGE_RENDER_TARGET;
+
+ p->tex = p->screen->texture_create(p->screen, &t_tmplt);
+
+ t = p->pipe->get_tex_transfer(p->pipe, p->tex,
+ 0, 0, 0, /* face, level, zslice */
+ PIPE_TRANSFER_WRITE,
+ 0, 0, 2, 2); /* x, y, width, height */
+
+ ptr = p->pipe->transfer_map(p->pipe, t);
+ ptr[0] = 0xffff0000;
+ ptr[1] = 0xff0000ff;
+ ptr[2] = 0xff00ff00;
+ ptr[3] = 0xffffff00;
+ p->pipe->transfer_unmap(p->pipe, t);
+
+ p->pipe->tex_transfer_destroy(p->pipe, t);
+
+ u_sampler_view_default_template(&v_tmplt, p->tex, p->tex->format);
+
+ p->view = p->pipe->create_sampler_view(p->pipe, p->tex, &v_tmplt);
+ }
+
+ /* disabled blending/masking */
+ memset(&p->blend, 0, sizeof(p->blend));
+ p->blend.rt[0].colormask = PIPE_MASK_RGBA;
+
+ /* no-op depth/stencil/alpha */
+ memset(&p->depthstencil, 0, sizeof(p->depthstencil));
+
+ /* rasterizer */
+ memset(&p->rasterizer, 0, sizeof(p->rasterizer));
+ p->rasterizer.front_winding = PIPE_WINDING_CW;
+ p->rasterizer.cull_mode = PIPE_WINDING_NONE;
+ p->rasterizer.gl_rasterization_rules = 1;
+
+ /* sampler */
+ memset(&p->sampler, 0, sizeof(p->sampler));
+ p->sampler.wrap_s = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
+ p->sampler.wrap_t = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
+ p->sampler.wrap_r = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
+ p->sampler.min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
+ p->sampler.min_img_filter = PIPE_TEX_MIPFILTER_LINEAR;
+ p->sampler.mag_img_filter = PIPE_TEX_MIPFILTER_LINEAR;
+ p->sampler.normalized_coords = 1;
+
+ /* drawing destination */
+ memset(&p->framebuffer, 0, sizeof(p->framebuffer));
+ p->framebuffer.width = WIDTH;
+ p->framebuffer.height = HEIGHT;
+ p->framebuffer.nr_cbufs = 1;
+ p->framebuffer.cbufs[0] = p->screen->get_tex_surface(p->screen, p->target, 0, 0, 0, PIPE_BUFFER_USAGE_GPU_WRITE);
+
+ /* viewport, depth isn't really needed */
+ {
+ float x = 0;
+ float y = 0;
+ float z = FAR;
+ float half_width = (float)WIDTH / 2.0f;
+ float half_height = (float)HEIGHT / 2.0f;
+ float half_depth = ((float)FAR - (float)NEAR) / 2.0f;
+ float scale, bias;
+
+ if (FLIP) {
+ scale = -1.0f;
+ bias = (float)HEIGHT;
+ } else {
+ scale = 1.0f;
+ bias = 0.0f;
+ }
+
+ p->viewport.scale[0] = half_width;
+ p->viewport.scale[1] = half_height * scale;
+ p->viewport.scale[2] = half_depth;
+ p->viewport.scale[3] = 1.0f;
+
+ p->viewport.translate[0] = half_width + x;
+ p->viewport.translate[1] = (half_height + y) * scale + bias;
+ p->viewport.translate[2] = half_depth + z;
+ p->viewport.translate[3] = 0.0f;
+ }
+
+ /* vertex elements state */
+ memset(p->velem, 0, sizeof(p->velem));
+ p->velem[0].src_offset = 0 * 4 * sizeof(float); /* offset 0, first element */
+ p->velem[0].instance_divisor = 0;
+ p->velem[0].vertex_buffer_index = 0;
+ p->velem[0].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
+
+ p->velem[1].src_offset = 1 * 4 * sizeof(float); /* offset 16, second element */
+ p->velem[1].instance_divisor = 0;
+ p->velem[1].vertex_buffer_index = 0;
+ p->velem[1].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
+
+ /* vertex shader */
+ {
+ const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
+ TGSI_SEMANTIC_GENERIC };
+ const uint semantic_indexes[] = { 0, 0 };
+ p->vs = util_make_vertex_passthrough_shader(p->pipe, 2, semantic_names, semantic_indexes);
+ }
+
+ /* fragment shader */
+ p->fs = util_make_fragment_tex_shader(p->pipe, TGSI_TEXTURE_2D);
+}
+
+static void close_prog(struct program *p)
+{
+ /* unset bound textures as well */
+ cso_set_fragment_sampler_views(p->cso, 0, NULL);
+
+ /* unset all state */
+ cso_release_all(p->cso);
+
+ p->pipe->delete_vs_state(p->pipe, p->vs);
+ p->pipe->delete_fs_state(p->pipe, p->fs);
+
+ pipe_surface_reference(&p->framebuffer.cbufs[0], NULL);
+ pipe_sampler_view_reference(&p->view, NULL);
+ pipe_texture_reference(&p->target, NULL);
+ pipe_texture_reference(&p->tex, NULL);
+ pipe_buffer_reference(&p->vbuf, NULL);
+
+ cso_destroy_context(p->cso);
+ p->pipe->destroy(p->pipe);
+ p->screen->destroy(p->screen);
+
+ FREE(p);
+}
+
+static void draw(struct program *p)
+{
+ /* set the render target */
+ cso_set_framebuffer(p->cso, &p->framebuffer);
+
+ /* clear the render target */
+ p->pipe->clear(p->pipe, PIPE_CLEAR_COLOR, p->clear_color, 0, 0);
+
+ /* set misc state we care about */
+ cso_set_blend(p->cso, &p->blend);
+ cso_set_depth_stencil_alpha(p->cso, &p->depthstencil);
+ cso_set_rasterizer(p->cso, &p->rasterizer);
+ cso_set_viewport(p->cso, &p->viewport);
+
+ /* sampler */
+ cso_single_sampler(p->cso, 0, &p->sampler);
+ cso_single_sampler_done(p->cso);
+
+ /* texture sampler view */
+ cso_set_fragment_sampler_views(p->cso, 1, &p->view);
+
+ /* shaders */
+ cso_set_fragment_shader_handle(p->cso, p->fs);
+ cso_set_vertex_shader_handle(p->cso, p->vs);
+
+ /* vertex element data */
+ cso_set_vertex_elements(p->cso, 2, p->velem);
+
+ util_draw_vertex_buffer(p->pipe,
+ p->vbuf, 0,
+ PIPE_PRIM_QUADS,
+ 4, /* verts */
+ 2); /* attribs/vert */
+
+ p->pipe->flush(p->pipe, PIPE_FLUSH_RENDER_CACHE, NULL);
+
+ debug_dump_surface_bmp(p->pipe, "result.bmp", p->framebuffer.cbufs[0]);
+}
+
+int main(int argc, char** argv)
+{
+ struct program *p = CALLOC_STRUCT(program);
+
+ init_prog(p);
+ draw(p);
+ close_prog(p);
+
+ return 0;
+}
--- /dev/null
+/**************************************************************************
+ *
+ * Copyright © 2010 Jakob Bornecrantz
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+#define USE_TRACE 0
+#define WIDTH 300
+#define HEIGHT 300
+#define NEAR 30
+#define FAR 1000
+#define FLIP 0
+
+/* pipe_*_state structs */
+#include "pipe/p_state.h"
+/* pipe_context */
+#include "pipe/p_context.h"
+/* pipe_screen */
+#include "pipe/p_screen.h"
+/* PIPE_* */
+#include "pipe/p_defines.h"
+/* TGSI_SEMANTIC_{POSITION|GENERIC} */
+#include "pipe/p_shader_tokens.h"
+/* pipe_buffer_* helpers */
+#include "util/u_inlines.h"
+
+/* constant state object helper */
+#include "cso_cache/cso_context.h"
+
+/* debug_dump_surface_bmp */
+#include "util/u_debug.h"
+/* util_draw_vertex_buffer helper */
+#include "util/u_draw_quad.h"
+/* FREE & CALLOC_STRUCT */
+#include "util/u_memory.h"
+/* util_make_[fragment|vertex]_passthrough_shader */
+#include "util/u_simple_shaders.h"
+
+/* softpipe software driver */
+#include "softpipe/sp_public.h"
+
+/* null software winsys */
+#include "sw/null/null_sw_winsys.h"
+
+/* traceing support see src/gallium/drivers/trace/README for more info. */
+#if USE_TRACE
+#include "trace/tr_screen.h"
+#include "trace/tr_context.h"
+#endif
+
+struct program
+{
+ struct pipe_screen *screen;
+ struct pipe_context *pipe;
+ struct cso_context *cso;
+
+ struct pipe_blend_state blend;
+ struct pipe_depth_stencil_alpha_state depthstencil;
+ struct pipe_rasterizer_state rasterizer;
+ struct pipe_viewport_state viewport;
+ struct pipe_framebuffer_state framebuffer;
+ struct pipe_vertex_element velem[2];
+
+ void *vs;
+ void *fs;
+
+ float clear_color[4];
+
+ struct pipe_buffer *vbuf;
+ struct pipe_texture *target;
+};
+
+static void init_prog(struct program *p)
+{
+ /* create the software rasterizer */
+ p->screen = softpipe_create_screen(null_sw_create());
+#if USE_TRACE
+ p->screen = trace_screen_create(p->screen);
+#endif
+ p->pipe = p->screen->context_create(p->screen, NULL);
+ p->cso = cso_create_context(p->pipe);
+
+ /* set clear color */
+ p->clear_color[0] = 0.3;
+ p->clear_color[1] = 0.1;
+ p->clear_color[2] = 0.3;
+ p->clear_color[3] = 1.0;
+
+ /* vertex buffer */
+ {
+ float vertices[4][2][4] = {
+ {
+ { 0.0f, -0.9f, 0.0f, 1.0f },
+ { 1.0f, 0.0f, 0.0f, 1.0f }
+ },
+ {
+ { -0.9f, 0.9f, 0.0f, 1.0f },
+ { 0.0f, 1.0f, 0.0f, 1.0f }
+ },
+ {
+ { 0.9f, 0.9f, 0.0f, 1.0f },
+ { 0.0f, 0.0f, 1.0f, 1.0f }
+ }
+ };
+
+ p->vbuf = pipe_buffer_create(p->screen, 16, PIPE_BUFFER_USAGE_VERTEX, sizeof(vertices));
+ pipe_buffer_write(p->screen, p->vbuf, 0, sizeof(vertices), vertices);
+ }
+
+ /* render target texture */
+ {
+ struct pipe_texture tmplt;
+ memset(&tmplt, 0, sizeof(tmplt));
+ tmplt.target = PIPE_TEXTURE_2D;
+ tmplt.format = PIPE_FORMAT_B8G8R8A8_UNORM; /* All drivers support this */
+ tmplt.width0 = WIDTH;
+ tmplt.height0 = HEIGHT;
+ tmplt.depth0 = 1;
+ tmplt.last_level = 0;
+ tmplt.tex_usage = PIPE_TEXTURE_USAGE_RENDER_TARGET;
+
+ p->target = p->screen->texture_create(p->screen, &tmplt);
+ }
+
+ /* disabled blending/masking */
+ memset(&p->blend, 0, sizeof(p->blend));
+ p->blend.rt[0].colormask = PIPE_MASK_RGBA;
+
+ /* no-op depth/stencil/alpha */
+ memset(&p->depthstencil, 0, sizeof(p->depthstencil));
+
+ /* rasterizer */
+ memset(&p->rasterizer, 0, sizeof(p->rasterizer));
+ p->rasterizer.front_winding = PIPE_WINDING_CW;
+ p->rasterizer.cull_mode = PIPE_WINDING_NONE;
+ p->rasterizer.gl_rasterization_rules = 1;
+
+ /* drawing destination */
+ memset(&p->framebuffer, 0, sizeof(p->framebuffer));
+ p->framebuffer.width = WIDTH;
+ p->framebuffer.height = HEIGHT;
+ p->framebuffer.nr_cbufs = 1;
+ p->framebuffer.cbufs[0] = p->screen->get_tex_surface(p->screen, p->target, 0, 0, 0, PIPE_BUFFER_USAGE_GPU_WRITE);
+
+ /* viewport, depth isn't really needed */
+ {
+ float x = 0;
+ float y = 0;
+ float z = FAR;
+ float half_width = (float)WIDTH / 2.0f;
+ float half_height = (float)HEIGHT / 2.0f;
+ float half_depth = ((float)FAR - (float)NEAR) / 2.0f;
+ float scale, bias;
+
+ if (FLIP) {
+ scale = -1.0f;
+ bias = (float)HEIGHT;
+ } else {
+ scale = 1.0f;
+ bias = 0.0f;
+ }
+
+ p->viewport.scale[0] = half_width;
+ p->viewport.scale[1] = half_height * scale;
+ p->viewport.scale[2] = half_depth;
+ p->viewport.scale[3] = 1.0f;
+
+ p->viewport.translate[0] = half_width + x;
+ p->viewport.translate[1] = (half_height + y) * scale + bias;
+ p->viewport.translate[2] = half_depth + z;
+ p->viewport.translate[3] = 0.0f;
+ }
+
+ /* vertex elements state */
+ memset(p->velem, 0, sizeof(p->velem));
+ p->velem[0].src_offset = 0 * 4 * sizeof(float); /* offset 0, first element */
+ p->velem[0].instance_divisor = 0;
+ p->velem[0].vertex_buffer_index = 0;
+ p->velem[0].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
+
+ p->velem[1].src_offset = 1 * 4 * sizeof(float); /* offset 16, second element */
+ p->velem[1].instance_divisor = 0;
+ p->velem[1].vertex_buffer_index = 0;
+ p->velem[1].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
+
+ /* vertex shader */
+ {
+ const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
+ TGSI_SEMANTIC_COLOR };
+ const uint semantic_indexes[] = { 0, 0 };
+ p->vs = util_make_vertex_passthrough_shader(p->pipe, 2, semantic_names, semantic_indexes);
+ }
+
+ /* fragment shader */
+ p->fs = util_make_fragment_passthrough_shader(p->pipe);
+}
+
+static void close_prog(struct program *p)
+{
+ /* unset all state */
+ cso_release_all(p->cso);
+
+ p->pipe->delete_vs_state(p->pipe, p->vs);
+ p->pipe->delete_fs_state(p->pipe, p->fs);
+
+ pipe_surface_reference(&p->framebuffer.cbufs[0], NULL);
+ pipe_texture_reference(&p->target, NULL);
+ pipe_buffer_reference(&p->vbuf, NULL);
+
+ cso_destroy_context(p->cso);
+ p->pipe->destroy(p->pipe);
+ p->screen->destroy(p->screen);
+
+ FREE(p);
+}
+
+static void draw(struct program *p)
+{
+ /* set the render target */
+ cso_set_framebuffer(p->cso, &p->framebuffer);
+
+ /* clear the render target */
+ p->pipe->clear(p->pipe, PIPE_CLEAR_COLOR, p->clear_color, 0, 0);
+
+ /* set misc state we care about */
+ cso_set_blend(p->cso, &p->blend);
+ cso_set_depth_stencil_alpha(p->cso, &p->depthstencil);
+ cso_set_rasterizer(p->cso, &p->rasterizer);
+ cso_set_viewport(p->cso, &p->viewport);
+
+ /* shaders */
+ cso_set_fragment_shader_handle(p->cso, p->fs);
+ cso_set_vertex_shader_handle(p->cso, p->vs);
+
+ /* vertex element data */
+ cso_set_vertex_elements(p->cso, 2, p->velem);
+
+ util_draw_vertex_buffer(p->pipe,
+ p->vbuf, 0,
+ PIPE_PRIM_TRIANGLES,
+ 3, /* verts */
+ 2); /* attribs/vert */
+
+ p->pipe->flush(p->pipe, PIPE_FLUSH_RENDER_CACHE, NULL);
+
+ debug_dump_surface_bmp(p->pipe, "result.bmp", p->framebuffer.cbufs[0]);
+}
+
+int main(int argc, char** argv)
+{
+ struct program *p = CALLOC_STRUCT(program);
+
+ init_prog(p);
+ draw(p);
+ close_prog(p);
+
+ return 0;
+}
projects / mesa.git / commitdiff