/* * Copyright © 2009 Intel Corporation * * 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. * * Authors: * Eric Anholt * */ #include "brw_context.h" #include "brw_state.h" #include "brw_defines.h" #include "intel_batchbuffer.h" #include "main/fbobject.h" #include "main/framebuffer.h" #include "main/viewport.h" void brw_calculate_guardband_size(const struct gen_device_info *devinfo, uint32_t fb_width, uint32_t fb_height, float m00, float m11, float m30, float m31, float *xmin, float *xmax, float *ymin, float *ymax) { /* According to the "Vertex X,Y Clamping and Quantization" section of the * Strips and Fans documentation: * * "The vertex X and Y screen-space coordinates are also /clamped/ to the * fixed-point "guardband" range supported by the rasterization hardware" * * and * * "In almost all circumstances, if an object’s vertices are actually * modified by this clamping (i.e., had X or Y coordinates outside of * the guardband extent the rendered object will not match the intended * result. Therefore software should take steps to ensure that this does * not happen - e.g., by clipping objects such that they do not exceed * these limits after the Drawing Rectangle is applied." * * I believe the fundamental restriction is that the rasterizer (in * the SF/WM stages) have a limit on the number of pixels that can be * rasterized. We need to ensure any coordinates beyond the rasterizer * limit are handled by the clipper. So effectively that limit becomes * the clipper's guardband size. * * It goes on to say: * * "In addition, in order to be correctly rendered, objects must have a * screenspace bounding box not exceeding 8K in the X or Y direction. * This additional restriction must also be comprehended by software, * i.e., enforced by use of clipping." * * This makes no sense. Gen7+ hardware supports 16K render targets, * and you definitely need to be able to draw polygons that fill the * surface. Our assumption is that the rasterizer was limited to 8K * on Sandybridge, which only supports 8K surfaces, and it was actually * increased to 16K on Ivybridge and later. * * So, limit the guardband to 16K on Gen7+ and 8K on Sandybridge. */ const float gb_size = devinfo->gen >= 7 ? 16384.0f : 8192.0f; if (m00 != 0 && m11 != 0) { /* First, we compute the screen-space render area */ const float ss_ra_xmin = MIN3( 0, m30 + m00, m30 - m00); const float ss_ra_xmax = MAX3( fb_width, m30 + m00, m30 - m00); const float ss_ra_ymin = MIN3( 0, m31 + m11, m31 - m11); const float ss_ra_ymax = MAX3(fb_height, m31 + m11, m31 - m11); /* We want the guardband to be centered on that */ const float ss_gb_xmin = (ss_ra_xmin + ss_ra_xmax) / 2 - gb_size; const float ss_gb_xmax = (ss_ra_xmin + ss_ra_xmax) / 2 + gb_size; const float ss_gb_ymin = (ss_ra_ymin + ss_ra_ymax) / 2 - gb_size; const float ss_gb_ymax = (ss_ra_ymin + ss_ra_ymax) / 2 + gb_size; /* Now we need it in native device coordinates */ const float ndc_gb_xmin = (ss_gb_xmin - m30) / m00; const float ndc_gb_xmax = (ss_gb_xmax - m30) / m00; const float ndc_gb_ymin = (ss_gb_ymin - m31) / m11; const float ndc_gb_ymax = (ss_gb_ymax - m31) / m11; /* Thanks to Y-flipping and ORIGIN_UPPER_LEFT, the Y coordinates may be * flipped upside-down. X should be fine though. */ assert(ndc_gb_xmin <= ndc_gb_xmax); *xmin = ndc_gb_xmin; *xmax = ndc_gb_xmax; *ymin = MIN2(ndc_gb_ymin, ndc_gb_ymax); *ymax = MAX2(ndc_gb_ymin, ndc_gb_ymax); } else { /* The viewport scales to 0, so nothing will be rendered. */ *xmin = 0.0f; *xmax = 0.0f; *ymin = 0.0f; *ymax = 0.0f; } } static void gen6_upload_sf_and_clip_viewports(struct brw_context *brw) { struct gl_context *ctx = &brw->ctx; const struct gen_device_info *devinfo = &brw->screen->devinfo; struct gen6_sf_viewport *sfv; struct brw_clipper_viewport *clv; GLfloat y_scale, y_bias; /* BRW_NEW_VIEWPORT_COUNT */ const unsigned viewport_count = brw->clip.viewport_count; /* _NEW_BUFFERS */ struct gl_framebuffer *fb = ctx->DrawBuffer; const bool render_to_fbo = _mesa_is_user_fbo(fb); const uint32_t fb_width = _mesa_geometric_width(ctx->DrawBuffer); const uint32_t fb_height = _mesa_geometric_height(ctx->DrawBuffer); sfv = brw_state_batch(brw, sizeof(*sfv) * viewport_count, 32, &brw->sf.vp_offset); memset(sfv, 0, sizeof(*sfv) * viewport_count); clv = brw_state_batch(brw, sizeof(*clv) * viewport_count, 32, &brw->clip.vp_offset); if (render_to_fbo) { y_scale = 1.0; y_bias = 0.0; } else { y_scale = -1.0; y_bias = (float)fb_height; } for (unsigned i = 0; i < viewport_count; i++) { float scale[3], translate[3]; /* _NEW_VIEWPORT */ _mesa_get_viewport_xform(ctx, i, scale, translate); sfv[i].m00 = scale[0]; sfv[i].m11 = scale[1] * y_scale; sfv[i].m22 = scale[2]; sfv[i].m30 = translate[0]; sfv[i].m31 = translate[1] * y_scale + y_bias; sfv[i].m32 = translate[2]; brw_calculate_guardband_size(devinfo, fb_width, fb_height, sfv[i].m00, sfv[i].m11, sfv[i].m30, sfv[i].m31, &clv[i].xmin, &clv[i].xmax, &clv[i].ymin, &clv[i].ymax); } brw->ctx.NewDriverState |= BRW_NEW_SF_VP | BRW_NEW_CLIP_VP; } const struct brw_tracked_state gen6_sf_and_clip_viewports = { .dirty = { .mesa = _NEW_BUFFERS | _NEW_VIEWPORT, .brw = BRW_NEW_BATCH | BRW_NEW_BLORP | BRW_NEW_VIEWPORT_COUNT, }, .emit = gen6_upload_sf_and_clip_viewports, }; static void upload_viewport_state_pointers(struct brw_context *brw) { BEGIN_BATCH(4); OUT_BATCH(_3DSTATE_VIEWPORT_STATE_POINTERS << 16 | (4 - 2) | GEN6_CC_VIEWPORT_MODIFY | GEN6_SF_VIEWPORT_MODIFY | GEN6_CLIP_VIEWPORT_MODIFY); OUT_BATCH(brw->clip.vp_offset); OUT_BATCH(brw->sf.vp_offset); OUT_BATCH(brw->cc.vp_offset); ADVANCE_BATCH(); } const struct brw_tracked_state gen6_viewport_state = { .dirty = { .mesa = 0, .brw = BRW_NEW_BATCH | BRW_NEW_BLORP | BRW_NEW_CC_VP | BRW_NEW_CLIP_VP | BRW_NEW_SF_VP | BRW_NEW_STATE_BASE_ADDRESS, }, .emit = upload_viewport_state_pointers, };