From: Ian Romanick Date: Wed, 8 Jan 2014 20:10:41 +0000 (-0800) Subject: mesa: Refactor bounding-box calculation out of _mesa_update_draw_buffer_bounds X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a2b946cb3516eb3fd475e6ed509b3f09eb36d4b6;p=mesa.git mesa: Refactor bounding-box calculation out of _mesa_update_draw_buffer_bounds Drivers that currently use _Xmin and friends to set their scissor rectangle will need to use this code directly once they are updated for GL_ARB_viewport_array. v2: Use different bit-test idiom and fix mixed tabs and spaces. Both were suggested by Ken. Signed-off-by: Ian Romanick Reviewed-by: Kenneth Graunke --- diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c index f14f7a4877e..bd8f4933ff1 100644 --- a/src/mesa/main/framebuffer.c +++ b/src/mesa/main/framebuffer.c @@ -356,6 +356,56 @@ update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb) } +/** + * Calculate the inclusive bounding box for the scissor of a specific viewport + * + * \param ctx GL context. + * \param buffer Framebuffer to be checked against + * \param idx Index of the desired viewport + * \param bbox Bounding box for the scissored viewport. Stored as xmin, + * xmax, ymin, ymax. + * + * \warning This function assumes that the framebuffer dimensions are up to + * date (e.g., update_framebuffer_size has been recently called on \c buffer). + * + * \sa _mesa_clip_to_region + */ +void +_mesa_scissor_bounding_box(const struct gl_context *ctx, + const struct gl_framebuffer *buffer, + unsigned idx, int *bbox) +{ + bbox[0] = 0; + bbox[2] = 0; + bbox[1] = buffer->Width; + bbox[3] = buffer->Height; + + if (ctx->Scissor.EnableFlags & (1u << idx)) { + if (ctx->Scissor.ScissorArray[idx].X > bbox[0]) { + bbox[0] = ctx->Scissor.ScissorArray[idx].X; + } + if (ctx->Scissor.ScissorArray[idx].Y > bbox[2]) { + bbox[2] = ctx->Scissor.ScissorArray[idx].Y; + } + if (ctx->Scissor.ScissorArray[idx].X + ctx->Scissor.ScissorArray[idx].Width < bbox[1]) { + bbox[1] = ctx->Scissor.ScissorArray[idx].X + ctx->Scissor.ScissorArray[idx].Width; + } + if (ctx->Scissor.ScissorArray[idx].Y + ctx->Scissor.ScissorArray[idx].Height < bbox[3]) { + bbox[3] = ctx->Scissor.ScissorArray[idx].Y + ctx->Scissor.ScissorArray[idx].Height; + } + /* finally, check for empty region */ + if (bbox[0] > bbox[1]) { + bbox[0] = bbox[1]; + } + if (bbox[2] > bbox[3]) { + bbox[2] = bbox[3]; + } + } + + ASSERT(bbox[0] <= bbox[1]); + ASSERT(bbox[2] <= bbox[3]); +} + /** * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields. * These values are computed from the buffer's width and height and @@ -366,6 +416,7 @@ void _mesa_update_draw_buffer_bounds(struct gl_context *ctx) { struct gl_framebuffer *buffer = ctx->DrawBuffer; + int bbox[4]; if (!buffer) return; @@ -375,36 +426,12 @@ _mesa_update_draw_buffer_bounds(struct gl_context *ctx) update_framebuffer_size(ctx, buffer); } - buffer->_Xmin = 0; - buffer->_Ymin = 0; - buffer->_Xmax = buffer->Width; - buffer->_Ymax = buffer->Height; - /* Default to the first scissor as that's always valid */ - if (ctx->Scissor.EnableFlags & 1) { - if (ctx->Scissor.ScissorArray[0].X > buffer->_Xmin) { - buffer->_Xmin = ctx->Scissor.ScissorArray[0].X; - } - if (ctx->Scissor.ScissorArray[0].Y > buffer->_Ymin) { - buffer->_Ymin = ctx->Scissor.ScissorArray[0].Y; - } - if (ctx->Scissor.ScissorArray[0].X + ctx->Scissor.ScissorArray[0].Width < buffer->_Xmax) { - buffer->_Xmax = ctx->Scissor.ScissorArray[0].X + ctx->Scissor.ScissorArray[0].Width; - } - if (ctx->Scissor.ScissorArray[0].Y + ctx->Scissor.ScissorArray[0].Height < buffer->_Ymax) { - buffer->_Ymax = ctx->Scissor.ScissorArray[0].Y + ctx->Scissor.ScissorArray[0].Height; - } - /* finally, check for empty region */ - if (buffer->_Xmin > buffer->_Xmax) { - buffer->_Xmin = buffer->_Xmax; - } - if (buffer->_Ymin > buffer->_Ymax) { - buffer->_Ymin = buffer->_Ymax; - } - } - - ASSERT(buffer->_Xmin <= buffer->_Xmax); - ASSERT(buffer->_Ymin <= buffer->_Ymax); + _mesa_scissor_bounding_box(ctx, buffer, 0, bbox); + buffer->_Xmin = bbox[0]; + buffer->_Ymin = bbox[2]; + buffer->_Xmax = bbox[1]; + buffer->_Ymax = bbox[3]; } diff --git a/src/mesa/main/framebuffer.h b/src/mesa/main/framebuffer.h index 264566477dc..a4274216ec2 100644 --- a/src/mesa/main/framebuffer.h +++ b/src/mesa/main/framebuffer.h @@ -71,6 +71,11 @@ _mesa_resize_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb, extern void _mesa_resizebuffers( struct gl_context *ctx ); +extern void +_mesa_scissor_bounding_box(const struct gl_context *ctx, + const struct gl_framebuffer *buffer, + unsigned idx, int *bbox); + extern void _mesa_update_draw_buffer_bounds(struct gl_context *ctx);