/** * @name context_2d_bind * @brief bind's the given context to gl and enables / disables scissors * @param ctx - (context_2d *) context to bind * @retval NONE */ void context_2d_bind(context_2d *ctx) { if (tealeaf_canvas_context_2d_bind(ctx)) { if (IS_SCISSOR_ENABLED(ctx)) { enable_scissor(ctx); } else { disable_scissor(ctx); } } }
/** * @name context_2d_setClip * @brief sets the clipping rectangle on the given context * @param ctx - (context_2d *) context to set the clipping rectangle on * @param clip - (rect_2d) the clipping rectangle * @retval NONE */ void context_2d_setClip(context_2d *ctx, rect_2d clip) { matrix_3x3 *modelView = GET_MODEL_VIEW_MATRIX(ctx); // LOG("setClip: %f %f %f %f", clip.x, clip.y, clip.width, clip.height); // TODO: clipping with rectangles doesn't work so great with rotated or scaled coordinates... float x1, y1, x2, y2; matrix_3x3_multiply(modelView, clip.x, clip.y, &x1, &y1); matrix_3x3_multiply(modelView, clip.x + clip.width, clip.y + clip.height, &x2, &y2); clip.x = x1; clip.y = y1; clip.width = x2 - x1; clip.height = y2 - y1; int i = ctx->mvp - 1; rect_2d ctx_clip; ctx_clip.x = ctx->clipStack[i].x; ctx_clip.y = ctx->clipStack[i].y; ctx_clip.width = ctx->clipStack[i].width; ctx_clip.height = ctx->clipStack[i].height; //flip the y to be back at top left for easier readability of intersection testing if (ctx->on_screen && clip.height > 0) { ctx_clip.y = -ctx_clip.y + ctx->canvas->framebuffer_height + ctx->canvas->framebuffer_offset_bottom - ctx_clip.height; } //width = -1 if view is not clipping so ignore it if (ctx_clip.width > -1) { //set clip rect to empty if the clip coming in is outside of the clip stack's top clipping rect if (clip.x >= ctx_clip.x + ctx_clip.width || clip.x + clip.width <= ctx_clip.x || clip.y >= ctx_clip.y + ctx_clip.height || clip.y + clip.height <= ctx_clip.y) { clip.x = clip.y = clip.height = clip.width = 0; } else { clip.x = ctx_clip.x > x1 ? ctx_clip.x : x1; clip.y = ctx_clip.y > y1 ? ctx_clip.y : y1; clip.width = (ctx_clip.x + ctx_clip.width < x2 ? ctx_clip.x + ctx_clip.width : x2) - clip.x; clip.height = (ctx_clip.y + ctx_clip.height < y2 ? ctx_clip.y + ctx_clip.height : y2) - clip.y; } } // scissor is with respect to lower-left corner // activeFrameBufferHeight is the height of the off-screen buffer // activeFrameBufferOffsetBottom -- the viewport actually goes past the bottom of the texture // to the nearest power of two, so when we convert to y-coordinates from the lower-left viewport // corner, we need to add the offsetBottom to get to the bottom of the viewable texture if (ctx->on_screen && clip.height > 0) { clip.y = ctx->canvas->framebuffer_height - (clip.height + clip.y) + ctx->canvas->framebuffer_offset_bottom; } rect_2d bounds = {clip.x, clip.y, clip.width, clip.height}; if (rect_2d_equals(GET_CLIPPING_BOUNDS(ctx), &bounds)) { return; } *GET_CLIPPING_BOUNDS(ctx) = bounds; enable_scissor(ctx); }
/** * @name context_2d_restore * @brief pop's off the global properties stacks and resets glScissors * @param ctx - (context_2d *) context to restore * @retval NONE */ void context_2d_restore(context_2d *ctx) { ctx->mvp--; if (!rect_2d_equals(&ctx->clipStack[ctx->mvp], &ctx->clipStack[ctx->mvp + 1])) { if (ctx->clipStack[ctx->mvp].width == -1) { disable_scissor(ctx); } else { enable_scissor(ctx); } } }
/** * @name context_2d_restore * @brief pop's off the global properties stacks and resets glScissors * @param ctx - (context_2d *) context to restore * @retval NONE */ void context_2d_restore(context_2d *ctx) { int mvp = ctx->mvp - 1; // If stack still has items on it, if (mvp >= 0) { ctx->mvp = mvp; if (!rect_2d_equals(&ctx->clipStack[mvp], &ctx->clipStack[mvp + 1])) { if (ctx->clipStack[mvp].width == -1) { disable_scissor(ctx); } else { enable_scissor(ctx); } } } }
/** * @name context_2d_setClip * @brief sets the clipping rectangle on the given context * @param ctx - (context_2d *) context to set the clipping rectangle on * @param clip - (rect_2d) the clipping rectangle * @retval NONE */ void context_2d_setClip(context_2d *ctx, rect_2d clip) { matrix_3x3 *modelView = GET_MODEL_VIEW_MATRIX(ctx); #ifdef MATRIX_3x3_ALLOW_SKEW // TODO: Can this be done more efficiently? float clip_x, clip_y, clip_w, clip_h; float x1, y1, x2, y2, x3, y3, x4, y4; matrix_3x3_multiply(modelView, clip.x, clip.y, &x1, &y1); matrix_3x3_multiply(modelView, clip.x + clip.width, clip.y + clip.height, &x2, &y2); matrix_3x3_multiply(modelView, clip.x, clip.y + clip.height, &x3, &y3); matrix_3x3_multiply(modelView, clip.x + clip.width, clip.y, &x4, &y4); clip_x = x1; if (x2 < clip_x) { clip_x = x2; } if (x3 < clip_x) { clip_x = x3; } if (x4 < clip_x) { clip_x = x4; } clip_y = y1; if (y2 < clip_y) { clip_y = y2; } if (y3 < clip_y) { clip_y = y3; } if (y4 < clip_y) { clip_y = y4; } clip_w = x1; if (x2 > clip_w) { clip_w = x2; } if (x3 > clip_w) { clip_w = x3; } if (x4 > clip_w) { clip_w = x4; } clip_h = y1; if (y2 > clip_h) { clip_h = y2; } if (y3 > clip_h) { clip_h = y3; } if (y4 > clip_h) { clip_h = y4; } clip.x = clip_x; clip.y = clip_y; clip.width = clip_w - clip_x; clip.height = clip_h - clip_y; #else float clip0x = clip.x, clip0y = clip.y; float clip1x = clip0x + clip.width, clip1y = clip0y + clip.height; // float x1, y1, x2, y2, x3, y3, x4, y4; // x1 = clip0x * modelView->m00 + clip0y * modelView->m01 + modelView->m02; // y1 = clip0x * modelView->m10 + clip0y * modelView->m11 + modelView->m12; // x2 = clip1x * modelView->m00 + clip0y * modelView->m01 + modelView->m02; // y2 = clip1x * modelView->m10 + clip0y * modelView->m11 + modelView->m12; // x3 = clip1x * modelView->m00 + clip1y * modelView->m01 + modelView->m02; // y3 = clip1x * modelView->m10 + clip1y * modelView->m11 + modelView->m12; // x4 = clip0x * modelView->m00 + clip1y * modelView->m01 + modelView->m02; // y4 = clip0x * modelView->m10 + clip1y * modelView->m11 + modelView->m12; float m00 = modelView->m00, m01 = modelView->m01, m10 = modelView->m10, m11 = modelView->m11; float a = clip0x * m00; float b = clip1x * m10; float c = clip0y * m11; float d = clip0y * m01; float e = clip1x * m00; float f = clip1y * m01; float g = clip0x * m10; float h = clip1y * m11; // If x1 < x2, if ((clip0x < clip1x) ^ (m00 < 0)) { // If x2 < x3, if ((clip0y < clip1y) ^ (m01 < 0)) { // (x1, y2) -> (x3, y4) clip.x = a + d; clip.y = b + c; clip.width = e + f; clip.height = g + h; } else { // (x4, y1) -> (x2, y3) clip.x = a + f; clip.y = g + c; clip.width = e + d; clip.height = b + h; } } else { // If x2 < x3, if ((clip0y < clip1y) ^ (m01 < 0)) { // (x2, y3) -> (x4, y1) clip.x = e + d; clip.y = b + h; clip.width = a + f; clip.height = g + c; } else { // (x3, y4) -> (x1, y2) clip.x = e + f; clip.y = g + h; clip.width = a + d; clip.height = b + c; } } clip.width -= clip.x; clip.height -= clip.y; clip.x += modelView->m02; clip.y += modelView->m12; #endif // Clip with screen bounds if (clip.x < 0) { clip.width += clip.x; if (clip.width < 0) { clip.width = 0; } clip.x = 0; } if (clip.y < 0) { clip.height += clip.y; if (clip.height < 0) { clip.height = 0; } clip.y = 0; } // If entirely clipped, if (clip.width <= 0 || clip.height <= 0) { clip.x = clip.y = clip.width = clip.height = 0; } else { // Lookup parent bounds int i = ctx->mvp - 1; rect_2d ctx_clip; ctx_clip.x = ctx->clipStack[i].x; ctx_clip.y = ctx->clipStack[i].y; ctx_clip.width = ctx->clipStack[i].width; ctx_clip.height = ctx->clipStack[i].height; // If context is on screen, if (ctx->on_screen) { // Flip to frame buffer sense ctx_clip.y = -ctx_clip.y + ctx->canvas->framebuffer_height + ctx->canvas->framebuffer_offset_bottom - ctx_clip.height; } // If parent is clipping, if (ctx_clip.width > -1) { // Calculate (x1, y1) for new and old clip regions float clip1x = clip.x + clip.width, clip1y = clip.y + clip.height; float ctx1x = ctx_clip.x + ctx_clip.width, ctx1y = ctx_clip.y + ctx_clip.height; // If new clip is entirely outside parent, if (clip.x >= ctx1x || clip1x <= ctx_clip.x || clip.y >= ctx1y || clip1y <= ctx_clip.y) { // Empty clip region clip.x = clip.y = clip.width = clip.height = 0; } else { // Trim new clip with parent clip.x = ctx_clip.x > clip.x ? ctx_clip.x : clip.x; clip.y = ctx_clip.y > clip.y ? ctx_clip.y : clip.y; clip.width = (ctx1x < clip1x ? ctx1x : clip1x) - clip.x; clip.height = (ctx1y < clip1y ? ctx1y : clip1y) - clip.y; } } // scissor is with respect to lower-left corner // activeFrameBufferHeight is the height of the off-screen buffer // activeFrameBufferOffsetBottom -- the viewport actually goes past the bottom of the texture // to the nearest power of two, so when we convert to y-coordinates from the lower-left viewport // corner, we need to add the offsetBottom to get to the bottom of the viewable texture if (ctx->on_screen && clip.height > 0) { // Flip from frame buffer sense clip.y = ctx->canvas->framebuffer_height - (clip.height + clip.y) + ctx->canvas->framebuffer_offset_bottom; } } rect_2d bounds = { clip.x, clip.y, clip.width, clip.height }; if (rect_2d_equals(GET_CLIPPING_BOUNDS(ctx), &bounds)) { return; } *GET_CLIPPING_BOUNDS(ctx) = bounds; enable_scissor(ctx); }